All my UE4 files fail to build

Hi,
I am not sure what is going on but last night all of my UE4 file now fail to build. I brought home a scene file and put it into my db and renamed a few files but other than that nothing out of the normal. When I hit build it freezes and in the task manager it says that UE4 is not responding. Please help! I am showing a screen shot. I can open any scene file I have in my database and it does the same.